Effects of supercritical carbon dioxide conditions on onion oil desorption Original Research Article

Desorption of onion oil from adsorbent beds loaded with one liter of onion juice by supercritical carbon dioxide at different pressure, temperature, and density was investigated. At constant temperature; when density was increased from 0.69 to 0.86 g/ml at 37 °C, the gravimetric yield of onion oil by percentage was increased from 0.0112% to 0.0222%. When density was increased from 0.79 to 0.86 g/ml at 50 °C, the gravimetric yield of onion oil by percentage was increased from 0.0189% to 0.0231%. At constant density of 0.86 g/ml, an increase in temperature from 37 to 50 °C increased the gravimetric yield of onion oil by percentage from 0.0222% to 0.0231%. Yield difference was significant (p=0.05) only for the 0.69–0.86 g/ml density difference. Similar composition onion oil desorbed at the different supercritical carbon dioxide conditions was found by using GC-MS in the analysis of onion oil.